1. Field of the Invention
The present invention relates to an acoustic wave processing apparatus, a signal processing method, and a non-transitory computer readable recording medium storing a program for imaging an inspection object, such as an organ in a living body, by transmitting and receiving acoustic wave beams to generate acoustic wave images or the like used for the examination or diagnosis of the inspection object.
2. Description of the Related Art
In the field of medicine, acoustic-wave diagnostic apparatuses, such as ultrasonic image diagnostic apparatuses, that generate ultrasound images used for the examination or diagnosis of an inspection object by using acoustic waves, such as ultrasonic waves, are conventionally put to practical use.
This type of ultrasonic diagnostic apparatus typically has an ultrasonic probe (ultrasonic probe unit: hereinafter also referred to as “probe”) having a plurality of elements (ultrasonic transducers) built therein, and an apparatus body connected to the probe. The ultrasonic diagnostic apparatus transmits ultrasonic beams from the plurality of elements of the probe toward a subject (an inspection object) so as to form a predetermined focal point (transmit focal point), receives ultrasonic echoes from the subject by using the probe, and electrically processes reception signals of the received ultrasonic echoes by using the apparatus body to thereby generate an ultrasound image.
An ultrasonic beam is transmitted on the basis of a predetermined transmit delay pattern so as to drive a plurality of elements to form a set focal point. Such an ultrasonic beam is shaped to be wide in the lateral direction. This causes a problem in that information on a reflection point located at a laterally shifted position may be picked up and reproduced on an ultrasound image as a so-called “ghost” signal.
To address this problem, in the ultrasonic diagnostic apparatus, the generation of a single ultrasound image includes superimposing a plurality of pieces of data (element data or reception data) obtained via individual transmissions in accordance with reception times or the positions of the elements and correcting the pieces of data, called multi-line processing (JPS58-44372A (JP1983-44372A) and JP2009-536853A). Ghost signals are removable because the ghost signals are superimposed while being shifted with respect to each other and cancel each other out even if pieces of data are superimposed in accordance with reception times or the positions of the elements.